LITCHI crashed my drone!!!!

[Berzuo]

Hello everyone
, I had a terrible issue today with my P3SE, I was using litchi and flew in FPV manual wihtout any waypoint, around 1 km (i was in FCC mode though im in italy) the craft stopped and i seen the gimbal going flat, then a red error message appeared, something like "drone movement detected"i cant exaclty recall,
i got disconnected and the drone crashed!!!!first i waited some time for the RTH but nothing,
i went for the search of the drone in a wood but there is nothing in the last gps position and around..im so sad! is it normal? i read about litchi crashing drones after this experience...
here is the flight log, see that battery is ok and i was high in the sky, far from any objects, a bird maybe?

DJI Flight Log Viewer - PhantomHelp.com

how can this be possible? the drone to fall like a stone in this way??

 

[solentlife]

Litchhi will not cause a drone to fall out of the sky. If Litchi fails - the drone will default to the user setting of RTH or Land or Hover ... whichever you chose in the menu.

There are many reason this can happen :

battery failure

collision with object such as bird, branch, wire etc.

loss of prop or blade

Pilot error in flight commands

just to name a few.

Note - I have not checked out your Flight Log yet ...

Nigel

 

[solentlife]

At 1m 10.3s ... link lost ...
1m 25.9s .... link restored ... but it shows that ATTI mode is still active ...

If you were out there and ATTI mode was active - then the AC is basically unstable and could easily if you are not aware drift or change altitude such that it can crash.
ATTI mode requires that YOU the pilot provide full control to maintain all aspects of the flight ... the Flight Controller will only assist with command interpretation to the ESC / Motors.

The home distance is over 3200ft ... which I suggest in the urban environment you were taking off in is too far with a WiFi machine. Once it went ATTI - you were too far to get a display and had no idea of what was going on. Sorry - my honest opinion.

Nigel

 

[Berzuo]

At 1m 10.3s ... link lost ...
1m 25.9s .... link restored ... but it shows that ATTI mode is still active ...

If you were out there and ATTI mode was active - then the AC is basically unstable and could easily if you are not aware drift or change altitude such that it can crash.
ATTI mode requires that YOU the pilot provide full control to maintain all aspects of the flight ... the Flight Controller will only assist with command interpretation to the ESC / Motors.

The home distance is over 3200ft ... which I suggest in the urban environment you were taking off in is too far with a WiFi machine. Once it went ATTI - you were too far to get a display and had no idea of what was going on. Sorry - my honest opinion.

Nigel

ok but in this case it should trigger an RTH right? I mean even in atti mode and without me controlling the craft it should go home looking for my signal as usual!

 

[Fly Dawg]

ok but in this case it should trigger an RTH right? I mean even in atti mode and without me controlling the craft it should go home looking for my signal as usual!

No...There is no GPS while in ATTI mode. It must have GPS lock to RTH.

 

[solentlife]

No...There is no GPS while in ATTI mode. It must have GPS lock to RTH.

Actually its a little more than that. The manuals for P3's indicate that even in ATTI mode if there are sufficient Sats and Home Point has been recorded - it will still RTH.

I assume the P3SE will do same ...

Page 10 of Standard manual

Page 11 of Adv and Pro manual

The flight log shows that more than enough sats and link was restored - problem was that means RTH will NOT kick in and because hes unaware the AC is in ATTI mode ... he cannot do anything to save it.

Nigel

 

[Fly Dawg]

There is nothing in the data to indicate any sort of issue, other than as much as I hate to say it, "wreckless flying" IMO. Assuming that this was a bird strike, or some sort of mechanical failure on the aircraft, ignoring the RTH aspect. This may be very difficult to locate. I didn't take the time to do all the speed and distanace calculations other than your last speed and altitude, which was "WAY TOO HIGH AND FAST".....You would have had an angular fall which would put the aircraft far from the last recorded position. Taking a guess, possibly in the circular area below or farther.

 

[solentlife]

Hi Fly Dawg ... think you came to same conclusion as I ...

Those last lines in the log are the 'killer' ... he loses link - and the AC drops to ATTI ... he regains LINK but faiils to go back to P-GPS ... speed etc. show it stationary ... and we all know what happens with no input when ATTI ... its anyones guess where it ends up.

Nigel

 

[Fly Dawg]

Actually its a little more than that. The manuals for P3's indicate that even in ATTI mode if there are sufficient Sats and Home Point has been recorded - it will still RTH.

I agree that is what it says, but it makes no sense to me as to how the aircraft can RTH, even with a recorded home point without GPS lock to know where it is in the first place. Just because the home point is recorded on the aircraft, does not mean that it knows where that location is without a reference. Anyway, the SE manual reads slightly different.

 

[AuldGimpy]

Does flying FPV have any bearing in this discussion?
Just curious as no waypoint flight route would be available for flight completion.
Thanks. A.

 

[Berzuo]

There is nothing in the data to indicate any sort of issue, other than as much as I hate to say it, "wreckless flying" IMO. Assuming that this was a bird strike, or some sort of mechanical failure on the aircraft, ignoring the RTH aspect. This may be very difficult to locate. I didn't take the time to do all the speed and distanace calculations other than your last speed and altitude, which was "WAY TOO HIGH AND FAST".....You would have had an angular fall which would put the aircraft far from the last recorded position. Taking a guess, possibly in the circular area below or farther.


View attachment 107027

Wow, thank you very much for this! It seems like a very big area to search and there are some private properties I fear, tomorrow I’ll go with a few friends and look the area, in any case thanks for this graph

 

[Fly Dawg]

Does flying FPV have any bearing in this discussion?

It would really not make any difference. Had this been a waypoint mission (Which it wasn't ) the results would have been the same, assuming GPS Signal was lost.

Just curious as no waypoint flight route would be available for flight completion.

See the first answer.

 

[Berzuo]

But what can cause abrupt gps loss in a normal area?

 

[Fly Dawg]

But what can cause abrupt gps loss in a normal area?

We quite honestly do not know that you did. The data ends in ATTI mode at Zero Altitude which would be normal if the aircraft were on the ground, in the trees, or upside down. You lost signal for 15 seconds before ATTI mode showed up. It could have also been a compass error or any number of issues.

 

[Berzuo]

I was around 1km at cruising speed quite high, but didn’t anything very reckless, I was using litchi on iOS after switching to FCC with an android phone (which was shut and disconnected as well as rc/ac rebooted) the prior day I did a similar flight not more than 1km with the Android phone and dji 3.1.18 and all was fine, rth on dc etc. I don’t think this was a very reckless flight, perfect weather, full battery , drone almost new,no wind... I’m appalled!

 

[Fly Dawg]

I was around 1km at cruising speed quite high, but didn’t anything very reckless,

Just to clarify, It was the altitude that was disconcerting. Understandable if you are flying in mountain areas, but where your were flying far exceeded the altitude necessary for safe flight, winds can really pick up at that altitude and be dangerous to your aircraft. I am not sure of the altitude limits in Italy, but I fairly sure it is well under that.

 

[Fly Dawg]

I don’t think this was a very reckless flight

If this is correct, you were WAY over!

Italy Drone Laws

 

[Fly Dawg]

In specific, note the highlighted below:

 

[Berzuo]

If this is correct, you were WAY over!

Italy Drone Laws

I’m out of that law as 99.99% pilot in Italy because it’s just too strict, but the point is why a brand new drone designed to bear more than 300mt altidute in an anticyclone zone (zero winds) fails like that!

 

[solentlife]

I agree that is what it says, but it makes no sense to me as to how the aircraft can RTH, even with a recorded home point without GPS lock to know where it is in the first place. Just because the home point is recorded on the aircraft, does not mean that it knows where that location is without a reference. Anyway, the SE manual reads slightly different.

View attachment 107030

If you check his Log ... it shows more than enough SATS locked in ... but because the AC regained control link - it stayed there in ATTI mode.
If he had lost control link ... with the 16 SATS - it would have returned home ... there is no warning of no compass or anything ... its showing fine ...

Nigel